Period 0:  c. 8000 BCE - c. 1200 CE
Period 1: c. 1200 - c. 1450
     Unit 1:  The Global Tapestry from c. 1200 to c. 1450
     Unit 2:  Networks of Exchange from c. 1200 to c. 1450
Period 2:  c. 1450 - c. 1750
     Unit 3:  Land Based Empires from c. 1450 to c. 1750
     Unit 4:  Transoceanic Interconnections from c. 1450 to c. 1750     
Period 3:  c. 1750 - c. 1900
     Unit 5:  Revolutions from c. 1750 to c. 1900
     Unit 6:  Consequences of Industrialization from c. 1750 to c. 1900
Period 4: c. 1900 - Present
     Unit 7:  Global Conflict after 1900
     Unit 8:  Cold War and Decolonization
     Unit 9:  Globalization after 1900